US9636710B2 - Ultrasound element and ultrasound endoscope - Google Patents
Ultrasound element and ultrasound endoscope Download PDFInfo
- Publication number
- US9636710B2 US9636710B2 US14/152,058 US201414152058A US9636710B2 US 9636710 B2 US9636710 B2 US 9636710B2 US 201414152058 A US201414152058 A US 201414152058A US 9636710 B2 US9636710 B2 US 9636710B2
- Authority
- US
- United States
- Prior art keywords
- sections
- lower electrode
- ultrasound
- section
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active, expires
Links
- 238000002604 ultrasonography Methods 0.000 title claims abstract description 92
- 239000000758 substrate Substances 0.000 claims abstract description 11
- 238000005530 etching Methods 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 15
- 230000008569 process Effects 0.000 claims description 9
- 239000004020 conductor Substances 0.000 claims description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 abstract description 16
- 229910052710 silicon Inorganic materials 0.000 abstract description 8
- 239000010703 silicon Substances 0.000 abstract description 8
- 239000010410 layer Substances 0.000 description 78
- 238000004519 manufacturing process Methods 0.000 description 16
- 230000015572 biosynthetic process Effects 0.000 description 13
- 239000012528 membrane Substances 0.000 description 13
- 230000008859 change Effects 0.000 description 10
- 238000001514 detection method Methods 0.000 description 9
- 230000003071 parasitic effect Effects 0.000 description 8
- 230000009471 action Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 238000005452 bending Methods 0.000 description 5
- 238000003780 insertion Methods 0.000 description 5
- 230000037431 insertion Effects 0.000 description 5
- 229910052581 Si3N4 Inorganic materials 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 4
- 239000004642 Polyimide Substances 0.000 description 3
- 229920001721 polyimide Polymers 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000002405 diagnostic procedure Methods 0.000 description 2
- -1 for example Substances 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 239000002346 layers by function Substances 0.000 description 2
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 2
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 238000000206 photolithography Methods 0.000 description 2
- 102220090095 rs1042713 Human genes 0.000 description 2
- 102220029346 rs34541442 Human genes 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- BLIQUJLAJXRXSG-UHFFFAOYSA-N 1-benzyl-3-(trifluoromethyl)pyrrolidin-1-ium-3-carboxylate Chemical compound C1C(C(=O)O)(C(F)(F)F)CCN1CC1=CC=CC=C1 BLIQUJLAJXRXSG-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000012840 feeding operation Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/12—Diagnosis using ultrasonic, sonic or infrasonic waves in body cavities or body tracts, e.g. by using catheters
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
- A61B8/4444—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device related to the probe
- A61B8/445—Details of catheter construction
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
- A61B8/4483—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device characterised by features of the ultrasound transducer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/0292—Electrostatic transducers, e.g. electret-type
Definitions
- the present invention relates to an electrostatic capacitance type ultrasound element, and an ultrasound endoscope including the ultrasound element.
- An ultrasound diagnostic method by which an inside of a body is irradiated with ultrasound to image a state of the inside of the body from an echo signal for diagnosis comes into widespread use.
- One of the ultrasound diagnostic apparatuses for use in the ultrasound diagnostic method is an ultrasound endoscope (hereinafter called a “US endoscope”).
- a US endoscope an ultrasound transducer is placed at a distal end rigid portion of an insertion portion that is introduced into a body.
- An ultrasound transducer has a function of converting an electric signal into ultrasound, transmitting the ultrasound into a body, and receiving the ultrasound reflected at the inside of the body to convert the ultrasound into an electric signal.
- a c-MUT electrostatic capacitance ultrasound transducer (capacitive micromachined ultrasonic transducer; hereinafter called a “c-MUT”) that is produced with use of a MEMS (micro electro mechanical systems) technique, and does not contain lead in the material.
- a c-MUT has an ultrasound cell (hereinafter, called a “US cell”) in which an upper electrode section and a lower electrode section are disposed to face each other via a void portion (cavity), as a unit element.
- a plurality of US cells with respective electrode sections connected by wiring sections are arranged, and an ultrasound element (hereinafter, called a “US element”) is configured.
- the US cell vibrates a membrane (a vibration portion) including the upper electrode section by an electrostatic force by applying a voltage to between the lower electrode section and the upper electrode section, and generates ultrasound.
- a membrane a vibration portion
- the US cell vibrates a membrane (a vibration portion) including the upper electrode section by an electrostatic force by applying a voltage to between the lower electrode section and the upper electrode section, and generates ultrasound.
- ultrasound enters from an outside a space between both the electrodes changes, and therefore, the ultrasound is converted into an electric signal from a change of an electrostatic capacitance.
- the US cell has a structure in which a plurality of functional layers are stacked. Therefore, if the placement positions of patterns of upper and lower functional layers are misaligned, the characteristics are impaired. For example, if the lower electrode section and the upper electrode section are not placed in correct positions, the areas of the electrodes facing each other, in other words, effective electrode areas likely decrease.
- Japanese Patent Application Laid-Open Publication No. 2007-301023 discloses a c-MUT in which the size of an upper electrode section is smaller than the size of a cavity.
- the size of the upper electrode section is small, and therefore, the areas of the electrode sections facing each other are small, but even if the formation position of the upper electrode section is misaligned, the effective electrode areas do not change as long as the upper electrode section is located in a directly upper portion of the cavity.
- An ultrasound element of an embodiment of the present invention includes a base substrate, a lower electrode layer that has a plurality of lower electrode sections, and a plurality of lower wiring sections that connect the plurality of lower electrode sections, and is connected to a lower electrode terminal to which a drive signal and a bias signal are applied, a lower insulating layer, an upper insulating layer in which a plurality of cavities smaller than the respective lower electrode sections are formed, an upper electrode layer that has a plurality of upper electrode sections that are disposed to face the respective lower electrode sections via the respective cavities, and are smaller than the lower electrode sections and larger than the cavities, and a plurality of upper wiring sections that connect the plurality of upper electrode sections, and is connected to an upper electrode terminal at a ground potential that detects a capacitance signal, and a protection layer.
- an ultrasound endoscope of another embodiment of the present invention has an ultrasound element including a base substrate, a lower electrode layer that has a plurality of lower electrode sections, and a plurality of lower wiring sections that connect the plurality of lower electrode sections, and is connected to a lower electrode terminal to which a drive signal and a bias signal are applied, a lower insulating layer, an upper insulating layer in which a plurality of cavities smaller than the respective lower electrode sections are formed, an upper electrode layer that has a plurality of upper electrode sections that are disposed to face the respective lower electrode sections via the respective cavities, and are smaller than the lower electrode sections and larger than the cavities, and a plurality of upper wiring sections that connect the plurality of upper electrode sections, and is connected to an upper electrode terminal at a ground potential that detects a capacitance signal, and a protection layer.
- FIG. 1 is an external view for explaining an ultrasound endoscope of a first embodiment
- FIG. 2 is a perspective view for explaining a distal end portion of the ultrasound endoscope of the first embodiment
- FIG. 3 is a perspective view for explaining a configuration of an ultrasound array at the distal end portion of the ultrasound endoscope of the first embodiment
- FIG. 4 is a top view for explaining a structure of an ultrasound element of the first embodiment
- FIG. 5 is a partial sectional view taken along the V-V line of FIG. 4 , for explaining the structure of the ultrasound element of the first embodiment
- FIG. 6 is an exploded view for explaining a structure of an ultrasound cell of the first embodiment
- FIG. 7 is a schematic view for explaining an action of the ultrasound cell of the first embodiment
- FIG. 8 is a schematic view for explaining stacking misalignment of an ultrasound cell of a comparative example
- FIG. 9 is a schematic view for explaining stacking misalignment of the ultrasound cell of the first embodiment.
- FIG. 10 is a top view showing a pattern of a lower electrode layer of an ultrasound element of a second embodiment
- FIG. 11 is a top view showing a pattern of an upper electrode layer of the ultrasound element of the second embodiment
- FIG. 12 is an exploded view for explaining a structure of an ultrasound cell of the second embodiment
- FIG. 13A is a sectional view for explaining a manufacturing method of the ultrasound cell of the second embodiment
- FIG. 13B is a sectional view for explaining the manufacturing method of the ultrasound cell of the second embodiment
- FIG. 13C is a sectional view for explaining the manufacturing method of the ultrasound cell of the second embodiment
- FIG. 13D is a sectional view for explaining the manufacturing method of the ultrasound cell of the second embodiment
- FIG. 13E is a sectional view for explaining the manufacturing method of the ultrasound cell of the second embodiment
- FIG. 13F is a sectional view for explaining the manufacturing method of the ultrasound cell of the second embodiment.
- FIG. 14 is a top view showing a pattern of a sacrificial layer of the ultrasound cell of the second embodiment
- FIG. 15 is a top view showing a pattern of a shield electrode section of the ultrasound cell of the second embodiment
- FIG. 16 is a schematic view for explaining an action of the ultrasound cell of the second embodiment.
- FIG. 17 is a sectional view for explaining a structure of an ultrasound cell of a third embodiment.
- a US endoscope 2 configures an ultrasound endoscope system 1 with an ultrasound observation apparatus 3 and a monitor 4 .
- the US endoscope 2 includes an elongated insertion portion 21 that is inserted into a body, an operation portion 22 that is placed at a proximal end of the insertion portion 21 , and a universal cord 23 that is extended from a side portion of the operation portion 22 .
- a connector 24 A that is connected to a light source apparatus (not illustrated) is placed. From the connector 24 A, a cable 25 that is detachably connected to a camera control unit (not illustrated) via a connector 25 A, and a cable 26 that is detachably connected to the ultrasound observation apparatus 3 via a connector 26 A are extended.
- the monitor 4 is connected to the ultrasound observation apparatus 3 .
- the insertion portion 21 is configured by being connectively provided with a distal end rigid portion (hereinafter, called a “distal end portion”) 37 , a bending portion 38 that is located at a rear end of the distal end portion 37 , and a flexible tube portion 39 that is located at a rear end of the bending portion 38 to reach the operation portion 22 , has a small diameter, a long length and flexibility, in sequence from a distal end side.
- an ultrasound unit 30 is placed at a distal end side of the distal end portion 37 .
- an angle knob 22 A that performs bending control of the bending portion 38 to a desired direction
- an air feeding/water feeding button 22 B that performs an air feeding and a water feeding operations
- a suction button 22 C that performs a suction operation
- a treatment instrument insertion port 22 D that is an inlet port for a treatment instrument that is introduced into a body and the like are placed.
- an illumination lens cover 31 that configures an illumination optical system
- an observation lens cover 32 of an observation optical system a forceps port 33 that is also used as a suction port, and an air feeding/water feeding nozzle not illustrated are placed.
- an ultrasound array (US array) 40 of the US unit 30 is a radial type transducer group in which long sides of a plurality of ultrasound elements 20 rectangular in plain view are connected and roundly disposed in a cylinder shape.
- 200 of US elements 20 each with a short side of 0.1 mm or less are placed in a direction of 360 degrees on a side surface of a cylinder with a diameter of 2 mm, for example.
- the US array 40 is a radial type transducer group, but the US array may be a convex type transducer group that is folded into a convex shape.
- the coaxial cable bundle 35 includes coaxial cables having the same number of core wires as a total number of a plurality of signal lines 62 and a plurality of capacitance detection lines 61 .
- the coaxial cable bundle 35 is inserted through the distal end portion 37 , the bending portion 38 , the flexible tube portion 39 , the operation portion 22 , the universal cord 23 and the ultrasound cable 26 , and is connected to the ultrasound observation apparatus 3 via the ultrasound connector 26 A.
- a plurality of electrostatic capacitance type US cells 10 are disposed in a matrix shape. Note that for explanation, only some of the US cells 10 are shown in FIG. 4 . Disposition of the US cells 10 may be regular grid disposition, staggered disposition, triangular mesh disposition or the like, or may be random disposition. At one end portion of the US element 20 , the lower electrode terminal 52 is placed, and at the other end portion, the upper electrode terminal 51 is placed.
- a US cell 10 has, on a silicon substrate 11 that is a base substrate, a lower electrode layer 12 that is connected to the lower electrode terminal 52 , a lower insulating layer (a first insulating layer) 13 , an upper insulating layer (a second insulating layer) 15 in which cavities 14 in a cylindrical shape are formed, an upper electrode layer 16 that is connected to the upper electrode terminal 51 , and a protection layer (a third insulating layer) 17 , which are stacked in sequence.
- the silicon substrate 11 is a substrate in which silicon thermal oxide films 11 B and 11 C are formed on a surface of a silicon 11 A.
- the respective US cells 10 each have a lower electrode section 12 A and an upper electrode section 16 A that are disposed to face each other via the cavity 14 .
- the lower electrode layer 12 has a plurality of lower electrode sections 12 A that are circular in plain view, and a plurality of lower wiring sections 12 B that are provided extensively in two directions from edge side portions of the lower electrode sections 12 A.
- the lower wiring sections 12 B connect the lower electrode sections 12 A of another US cell of the same US element 20 .
- the lower wiring section 12 B is connected to the lower electrode terminal 52 .
- the upper electrode layer 16 has a plurality of upper electrode sections 16 A that are circular in plain view, and a plurality of upper wiring sections 16 B that are provided extensively in two directions from edge side portions of the upper electrode sections 16 A.
- the upper wiring sections 16 B connect the upper electrode sections 16 A of other US cells of the same US element 20 .
- the upper wiring sections 16 B are connected to the upper electrode terminals 51 .
- all the lower electrode sections 12 A of a plurality of US cells 10 that are disposed in the same US element 20 are connected to one another, and all the upper electrode sections 16 A are also connected to one another.
- the upper insulating layer 15 , the upper electrode layer 16 and the protection layer 17 in a region directly above the cavity 14 configure a membrane 18 that is a vibration section.
- the cavity 14 is smaller than the lower electrode section 12 A
- the upper electrode section 16 A is smaller than the lower electrode section 12 A and is larger than the cavity 14 .
- a diameter R12 of the lower electrode section 12 A, a diameter R14 of the cylindrical cavity 14 , and a diameter R16 of the upper electrode section 16 A all of which are in circle shapes in plain view are in the relation of the following (expression 1).
- the lower electrode section 12 A, the cavity 14 and the upper electrode section 16 A are placed in such a manner that centers of the respective circles correspond to a center line O that is perpendicular to the silicon substrate 11 .
- a section in which the lower electrode section 12 A and the upper electrode section 16 A are disposed to face each other via the cavity 14 is a variable capacitance section CE in which an electrostatic capacitance changes at a time of reception of ultrasound.
- the lower electrode section 12 A is connected to a voltage signal generating section 3 A of the ultrasound observation apparatus 3 via the lower electrode terminal 52 .
- the upper electrode section 16 A is connected to a capacitance signal detection section 3 B via the upper electrode terminal 51 to be at a ground potential.
- the capacitance signal detection section 3 B detects a capacitance signal (current change).
- the voltage signal generating section 3 A applies a drive voltage signal to the lower electrode section 12 A.
- the upper electrode section 16 A at the ground potential is drawn to the lower electrode section 12 A by an electrostatic force, and therefore, the membrane 18 that includes the upper electrode section 16 A deforms.
- the membrane 18 is restored to an original shape by an elastic force. By deformation/restoration of the membrane 18 , ultrasound is generated.
- the membrane 18 including the upper electrode section 16 A is deformed by the received ultrasound energy.
- a distance between the upper electrode section 16 A and the lower electrode section 12 A changes, and therefore, the electrostatic capacitance therebetween also changes.
- a current accompanying the capacitance change flows to the capacitance signal detection section 3 B. Namely, the received ultrasound energy is converted into a capacitance signal.
- the cavity 14 is formed at an upper side of the plurality of lower electrode sections 12 A so that the center line O is shared, and further on an upper side of the cavity 14 , the upper electrode section 16 A is formed so that the center line O is shared.
- stacking misalignment namely, stacking formation is not sometimes performed in a correct position.
- a US cell 110 of a comparative example shown in FIG. 8 sizes of an upper electrode section 116 A and a lower electrode section 112 A are smaller than that of a cavity 114 .
- stacking misalignment pattern misalignment of 0.5 ⁇ m, for example
- the variable capacitance section CE becomes small in the US cell 110 .
- sensitivity of the US cell 110 declines.
- a degree of stacking misalignment results from manufacturing variation, and therefore, characteristics of a US element 120 are unstable.
- the diameter R12 of the lower electrode section 12 A>the diameter R16 of the upper electrode section 16 A>R14 of the cavity 14 is satisfied, the above described effect is provided.
- variable capacitance section CE does not change even if stacking misalignment due to a manufacturing variation occurs, and therefore, the characteristics of the US element 20 and the US endoscope 2 are stable.
- the lower wiring section 12 B and the upper wiring section 16 B in longitudinal directions thereof of the US element 20 are orthogonal to each other. Namely, as shown in FIG. 10 , the lower wiring section 12 B is provided extensively in a Y axis direction from the lower electrode section 12 A, whereas as shown in FIG. 11 , the upper wiring section 16 B is provided extensively in an X axis direction from the upper electrode section 16 A.
- the electrostatic capacitance that is detected by the capacitance signal detection section 3 B is a total of the electrostatic capacitance and a parasitic capacitance of the variable capacitance section CE that is already described.
- the parasitic capacitance refers to an electrostatic capacitance of a capacitance fixation section, which does not change even if deformation of the membrane 18 occurs. For example, when the lower wiring section 12 B and the upper wiring section 16 B are disposed to face each other, a parasitic capacitance is generated therebetween.
- a US cell 10 A of the US element 20 A includes a shield electrode section 71 on an outer circumferential portion of the cavity 14 including a region in which an outer circumferential portion of the lower electrode section 12 A and an outer circumferential portion of the upper electrode section 16 A are disposed to face each other.
- the cavity 14 is a region in which a sacrificial layer 70 which is formed by a conductive material and covered with the upper insulating layer 15 is partially removed by an etching process
- the shield electrode section 71 is a remaining region of the sacrificial layer 70 that is not removed by the etching process.
- the shield electrode section 71 is connected to the shield electrode terminal 53 at the ground potential.
- a conductive material made of conductive silicon or a metal, for example, copper, gold or aluminum is deposited on an entire surface of the silicon substrate 11 by a sputtering method or the like. Subsequently, a mask pattern is formed by photolithography, and thereafter, is partially removed by etching, whereby the lower electrode layer 12 that has the lower electrode section 12 A and the lower wiring section 12 B is formed.
- the lower insulating layer 13 formed of an insulating material such as SiN is deposited by, for example, a CVD method (a chemical vapor deposition method) in such a manner as to cover the lower electrode layer 12 .
- Step S 13 Formation of the Sacrificial Layer
- a sacrificial layer material formed of a material that is selected from conductive materials and is removable by etching is deposited. Subsequently, a mask pattern 75 by photolithography is formed on the sacrificial layer 70 as shown in FIG. 13A .
- the sacrificial layer 70 is divided into a cavity section 72 in a shape of a cavity (columnar shape) and the shield electrode section 71 via a doughnut-shaped groove section 70 A by an etching process.
- a thickness of the sacrificial layer 70 corresponds to a height of the cavity 14 , and therefore, is, for example, 0.05 to 0.3 ⁇ m, and is preferably 0.05 to 0.15 ⁇ m.
- the upper insulating layer 15 is formed by the method and the material similar to those for the lower insulating layer 13 , for example. At this time, the upper insulating layer 15 A is also formed in an inside of the groove section 70 A, as already described.
- the upper insulating layer 15 is formed to cover the sacrificial layer pattern, and therefore, irregularities may occur due to the influence of the thickness of the sacrificial layer pattern. Then, insulation of the upper electrode layer that is formed on the upper insulating layer and the lower electrode layer is worsened, and action of the US cell sometimes becomes unstable.
- a surface thereof is preferably subjected to planarization.
- planarization for example, a chemical mechanical polishing method (CMP method) can be preferably used.
- the US element in which the top surface of the upper insulating layer is flat has stable characteristics.
- an opening portion (not illustrated) in which an etching agent is poured is formed in order to remove the cavity section 72 .
- Step S 16 Formation of the Cavity (Formation of the Shield Electrode Section)
- the cavity 14 is formed by removal of the cavity section 72 by etching.
- the shield electrode section 71 is separated from the cavity section 72 by the upper insulating layer 15 A, and therefore, is not removed by the etching agent. Namely, the shield electrode section 71 is the remaining region of the sacrificial layer 70 that is not removed by the etching process.
- tungsten W
- silicon nitride SiN
- a hydrogen peroxide solution H 2 O 2
- XeF 2 xenon difluoride gas
- the cavity 14 is not limited to being in a columnar shape, but may be in a polygonal column shape or the like.
- the shapes in plain view of the upper electrode section 16 A and the lower electrode section 12 A are also preferably formed into polygonal shapes.
- the patterns of the upper electrode section 16 A and the like can be in such sizes that a large pattern can contain a small pattern.
- the upper electrode layer 16 that has the upper electrode section 16 A and the upper wiring section 16 B is formed.
- the protection layer 17 has not only a protection function, but also a sound matching layer function, and a function of connecting the US element 20 .
- the lower electrode terminal 52 is also formed in the lower electrode forming step
- the upper electrode terminal 51 is also formed in the upper electrode forming step
- the shield electrode terminal 53 is also formed in the shield electrode forming step (sacrificial layer formation).
- the protection layer 17 is formed so as not to cover the lower electrode terminal 52 , the upper electrode terminal 51 and the shield electrode terminal 53 .
- the protection layer 17 is formed of a flexible resin such as polyimide, epoxy, acryl or poly-para-xylene, and is especially preferably formed of polyimide, because polyimide has high chemical resistance, has a curving property, and is easy to process. Note that the protection layer 17 may have a two-layer structure in which a second insulating layer having biocompatibility is further formed on a first insulating layer.
- a plurality of ultrasound elements 20 are roundly disposed in a radial shape with a predetermined diameter in a connecting direction, whereby the US array 40 is produced.
- the US array 40 is joined to an outer periphery of a cylinder with a predetermined diameter, for example.
- the coaxial cable bundle 35 is connected to the US array 40 , and the US unit 30 is produced.
- the lower electrode section 12 A is connected to the voltage signal generating section 3 A of the ultrasound observation apparatus 3 via the lower electrode terminal 52 .
- the shield electrode section 71 is at the ground potential via the shield electrode terminal 53 .
- the upper electrode section 16 A is connected to the capacitance signal detection section 3 B via the upper electrode terminal 51 to be at the ground potential.
- the capacitance signal detection section 3 B detects a capacitance signal (current change).
- the lower electrode section 12 A and the upper electrode section 16 A are disposed to face each other, in an outer circumferential region of the membrane 18 .
- the facing portion forms a capacitor, and is a parasitic capacitance section (fixed capacitance section) 19 in which an electrostatic capacitance does not change even when ultrasound is received.
- a parasitic capacitance section (fixed capacitance section) 19 in which an electrostatic capacitance does not change even when ultrasound is received.
- the shield electrode section 71 at the ground potential is placed on the outer circumferential portion where the lower electrode section 12 A and the upper electrode section 16 A are disposed to face each other. Therefore, the upper electrode section 16 A on the part where the lower electrode section 12 A and the shield electrode section 71 are disposed to face each other does not form a capacitor with the lower electrode section 12 A. Namely, the outer circumferential portion of the upper electrode section 16 A does not become a cause of a parasitic capacitance. Therefore, the US element 20 A has higher reception sensitivity of ultrasound than that of the US element 20 that does not have the shield electrode section 71 .
- the shield electrode section 74 is formed by the sacrificial layer 70 , and therefore, increase in the number of steps is small, and manufacture is easy.
- the upper side of the lower wiring section 12 B is covered with the shield electrode section 74 at the ground potential. Therefore, a voltage signal (a drive signal and a bias signal) that is applied to the lower wiring section 12 B does not leak outside the US element 20 A. Therefore, the characteristics of the US element 20 A and the US endoscope 2 A are further stable.
- the upper electrode section 16 A has a thickness of a central portion smaller than a thickness of the outer peripheral portion.
- the outer circumferential portion refers to a region that does not configure a membrane.
- a thickness of the upper wiring section 16 B is preferable the same thickness as the outer circumferential portion of the upper electrode section 16 A.
- the membrane 18 When the thickness of the central portion of the upper electrode section 16 A that configures the membrane 18 is small, the membrane 18 easily vibrates, and therefore, the US element 20 B having US cells 10 B and the US endoscope 2 B are highly sensitive.
- the thickness of the upper electrode section 16 A may be gradually thinner toward the central portion from the outer circumferential portion. Further, the upper electrode section 16 A that configures the membrane 18 may have a number of concave portions or through-holes. Namely, the thickness may be an average film thickness.
- the present invention is not limited to the embodiments described above, and various modifications, alterations and the like can be made within the range without changing the gist of the present invention.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Heart & Thoracic Surgery (AREA)
- Molecular Biology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Pathology (AREA)
- Radiology & Medical Imaging (AREA)
- Physics & Mathematics (AREA)
- Biomedical Technology (AREA)
- Veterinary Medicine (AREA)
- Medical Informatics (AREA)
- Biophysics (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Mechanical Engineering (AREA)
- Gynecology & Obstetrics (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
Abstract
Description
R12>R16>R14 (expression 1)
Claims (8)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011-153277 | 2011-07-11 | ||
JP2011153277A JP5855373B2 (en) | 2011-07-11 | 2011-07-11 | Ultrasound element and ultrasound endoscope |
PCT/JP2012/063793 WO2013008547A1 (en) | 2011-07-11 | 2012-05-29 | Ultrasonic element, and ultrasonic endoscope |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/063793 Continuation WO2013008547A1 (en) | 2011-07-11 | 2012-05-29 | Ultrasonic element, and ultrasonic endoscope |
PCT/JP2012/065379 Continuation WO2013002045A1 (en) | 2011-06-28 | 2012-06-15 | Fuel cell system |
Publications (2)
Publication Number | Publication Date |
---|---|
US20140128741A1 US20140128741A1 (en) | 2014-05-08 |
US9636710B2 true US9636710B2 (en) | 2017-05-02 |
Family
ID=47505845
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/152,058 Active 2034-04-15 US9636710B2 (en) | 2011-07-11 | 2014-01-10 | Ultrasound element and ultrasound endoscope |
Country Status (5)
Country | Link |
---|---|
US (1) | US9636710B2 (en) |
EP (1) | EP2733961B1 (en) |
JP (1) | JP5855373B2 (en) |
CN (1) | CN103597855B (en) |
WO (1) | WO2013008547A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5855374B2 (en) * | 2011-07-11 | 2016-02-09 | オリンパス株式会社 | Ultrasound element and ultrasound endoscope |
JP6833544B2 (en) * | 2017-02-09 | 2021-02-24 | キヤノン株式会社 | Capacitive transducer and its manufacturing method |
JP6465161B2 (en) * | 2017-06-13 | 2019-02-06 | セイコーエプソン株式会社 | Ultrasonic transducer device and ultrasonic measurement apparatus |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030006481A1 (en) | 2001-07-04 | 2003-01-09 | Matsushita Electric Industrial Co., Ltd. | Semiconductor integrated circuit, D-A converter device, and A-D converter device |
CN1820191A (en) | 2004-02-13 | 2006-08-16 | 东京毅力科创株式会社 | Capacitive sensor |
US20060179640A1 (en) | 2005-01-27 | 2006-08-17 | Hitachi, Ltd. | Ultrasonic transducer and method for manufacturing the same |
WO2006129525A1 (en) | 2005-05-31 | 2006-12-07 | Olympus Medical Systems Corp. | Capacitive micromachined ultrasonic transducer and method for manufacturing same |
WO2007099696A1 (en) | 2006-03-03 | 2007-09-07 | Olympus Medical Systems Corp. | Ultrasonic vibrator and body cavity ultrasonograph having the ultrasonic vibrator |
EP1837087A2 (en) | 2006-03-24 | 2007-09-26 | Hitachi, Ltd. | Ultrasonic transducer, ultrasonic probe and method for fabricating the same |
JP2007301023A (en) | 2006-05-09 | 2007-11-22 | Hitachi Medical Corp | Ultrasonic probe |
EP2030698A1 (en) | 2007-08-28 | 2009-03-04 | Olympus Medical Systems Corporation | Ultrasonic transducer, method of manufacturing ultrasonic transducer, ultrasonic diagnostic apparatus, and ultrasonic microscope |
CN101378605A (en) | 2007-08-28 | 2009-03-04 | 奥林巴斯医疗株式会社 | Ultrasonic transducer, method of manufacturing ultrasonic transducer, ultrasonic diagnostic apparatus, and ultrasonic microscope |
JP2009050560A (en) | 2007-08-28 | 2009-03-12 | Olympus Medical Systems Corp | Ultrasonic transducer, ultrasonic diagnostic system and ultrasonic microscope |
US20110154649A1 (en) | 2009-12-25 | 2011-06-30 | Canon Kabushiki Kaisha | Method of manufacturing capacitive electromechanical transducer |
US20140121526A1 (en) * | 2011-07-11 | 2014-05-01 | Olympus Corporation | Ultrasound element and ultrasound endoscope |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB0313041D0 (en) * | 2003-06-06 | 2003-07-09 | Koninkl Philips Electronics Nv | Display device having current-driven pixels |
JP2008099036A (en) * | 2006-10-12 | 2008-04-24 | Olympus Medical Systems Corp | Ultrasonic transducer, ultrasonic probe and ultrasonic diagnostic device |
-
2011
- 2011-07-11 JP JP2011153277A patent/JP5855373B2/en active Active
-
2012
- 2012-05-29 CN CN201280029137.9A patent/CN103597855B/en not_active Expired - Fee Related
- 2012-05-29 WO PCT/JP2012/063793 patent/WO2013008547A1/en active Application Filing
- 2012-05-29 EP EP12811508.6A patent/EP2733961B1/en active Active
-
2014
- 2014-01-10 US US14/152,058 patent/US9636710B2/en active Active
Patent Citations (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030006481A1 (en) | 2001-07-04 | 2003-01-09 | Matsushita Electric Industrial Co., Ltd. | Semiconductor integrated circuit, D-A converter device, and A-D converter device |
CN1820191A (en) | 2004-02-13 | 2006-08-16 | 东京毅力科创株式会社 | Capacitive sensor |
US20060179640A1 (en) | 2005-01-27 | 2006-08-17 | Hitachi, Ltd. | Ultrasonic transducer and method for manufacturing the same |
EP1897498A1 (en) | 2005-05-31 | 2008-03-12 | Olympus Medical Systems Corp. | Capacitive micromachined ultrasonic transducer and method for manufacturing same |
WO2006129525A1 (en) | 2005-05-31 | 2006-12-07 | Olympus Medical Systems Corp. | Capacitive micromachined ultrasonic transducer and method for manufacturing same |
JP2006333952A (en) | 2005-05-31 | 2006-12-14 | Olympus Medical Systems Corp | Capacitance ultrasonic trunsducer and its manufacturing method |
US20080067895A1 (en) | 2005-05-31 | 2008-03-20 | Olympus Medical Systems Corp. | Capacitive micromachined ultrasonic transducer and production method of same |
WO2007099696A1 (en) | 2006-03-03 | 2007-09-07 | Olympus Medical Systems Corp. | Ultrasonic vibrator and body cavity ultrasonograph having the ultrasonic vibrator |
JP2007229327A (en) | 2006-03-03 | 2007-09-13 | Olympus Medical Systems Corp | Ultrasonic vibrator and intracavitary ultrasonic diagnostic apparatus equipped with the same |
EP1992290A1 (en) | 2006-03-03 | 2008-11-19 | Olympus Medical Systems Corp. | Ultrasonic vibrator and body cavity ultrasonograph having the ultrasonic vibrator |
US20090076393A1 (en) | 2006-03-03 | 2009-03-19 | Olympus Medical Systems Corp. | Ultrasound transducer and endoscopic ultrasound diagnosis system including the same |
EP1837087A2 (en) | 2006-03-24 | 2007-09-26 | Hitachi, Ltd. | Ultrasonic transducer, ultrasonic probe and method for fabricating the same |
JP2007301023A (en) | 2006-05-09 | 2007-11-22 | Hitachi Medical Corp | Ultrasonic probe |
US20090058228A1 (en) | 2007-08-28 | 2009-03-05 | Olympus Medical Systems Corp. | Ultrasonic transducer, method of manufacturing ultrasonic transducer, ultrasonic diagnostic apparatus, and ultrasonic microscope |
CN101378605A (en) | 2007-08-28 | 2009-03-04 | 奥林巴斯医疗株式会社 | Ultrasonic transducer, method of manufacturing ultrasonic transducer, ultrasonic diagnostic apparatus, and ultrasonic microscope |
JP2009050560A (en) | 2007-08-28 | 2009-03-12 | Olympus Medical Systems Corp | Ultrasonic transducer, ultrasonic diagnostic system and ultrasonic microscope |
EP2030698A1 (en) | 2007-08-28 | 2009-03-04 | Olympus Medical Systems Corporation | Ultrasonic transducer, method of manufacturing ultrasonic transducer, ultrasonic diagnostic apparatus, and ultrasonic microscope |
US8047995B2 (en) | 2007-08-28 | 2011-11-01 | Olympus Medical Systems Corp. | Ultrasonic transducer, method of manufacturing ultrasonic transducer, ultrasonic diagnostic apparatus, and ultrasonic microscope |
US20110154649A1 (en) | 2009-12-25 | 2011-06-30 | Canon Kabushiki Kaisha | Method of manufacturing capacitive electromechanical transducer |
JP2011135408A (en) | 2009-12-25 | 2011-07-07 | Canon Inc | Method of manufacturing capacitive electromechanical transducer |
US20140121526A1 (en) * | 2011-07-11 | 2014-05-01 | Olympus Corporation | Ultrasound element and ultrasound endoscope |
Non-Patent Citations (2)
Title |
---|
Extended Supplementary European Search Report dated Mar. 9, 2015 from related European Application No. 12 81 1508.6. |
International Search Report dated Jul. 17, 2012 issued in PCT/JP2012/063793. |
Also Published As
Publication number | Publication date |
---|---|
JP5855373B2 (en) | 2016-02-09 |
US20140128741A1 (en) | 2014-05-08 |
EP2733961B1 (en) | 2017-08-09 |
JP2013021510A (en) | 2013-01-31 |
EP2733961A4 (en) | 2015-04-08 |
WO2013008547A1 (en) | 2013-01-17 |
CN103597855A (en) | 2014-02-19 |
CN103597855B (en) | 2016-10-19 |
EP2733961A1 (en) | 2014-05-21 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9525119B2 (en) | Flexible micromachined transducer device and method for fabricating same | |
US9629609B2 (en) | Ultrasound element and ultrasound endoscope | |
JP4632853B2 (en) | Capacitive ultrasonic transducer and manufacturing method thereof | |
US7952256B2 (en) | Ultrasonic transducer, ultrasonic transducer fabrication method, and ultrasonic endoscope | |
JP2009055473A (en) | Ultrasonic transducer, ultrasonic diagnostic equipment and ultrasonic microscope | |
US8512251B2 (en) | Ultrasound transducer and ultrasound diagnostic apparatus | |
US10016121B2 (en) | Ultrasound transducer element and ultrasound endoscope | |
US10342511B2 (en) | Ultrasound transducer element and ultrasound endoscope | |
JP5802448B2 (en) | Ultrasonic unit, ultrasonic endoscope, and method of manufacturing ultrasonic unit | |
US9636710B2 (en) | Ultrasound element and ultrasound endoscope | |
JP2013034665A (en) | Ultrasonic element and ultrasonic endoscope | |
JP4774394B2 (en) | Ultrasonic transducer, ultrasonic transducer manufacturing method, ultrasonic diagnostic apparatus, and ultrasonic microscope | |
JP5008946B2 (en) | Ultrasonic transducer, method for manufacturing ultrasonic transducer, and ultrasonic endoscope | |
JP2011035916A (en) | Ultrasonic endoscope | |
JP2013026735A (en) | Ultrasonic element and ultrasonic endoscope | |
JP2013098581A (en) | Ultrasonic unit, ultrasonic endoscope, and method for manufacturing ultrasonic unit |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: OLYMPUS CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MATSUMOTO, KAZUYA;KARAKI, KAZUHISA;HASEGAWA, MAMORU;AND OTHERS;SIGNING DATES FROM 20131129 TO 20131203;REEL/FRAME:031939/0386 Owner name: OLYMPUS MEDICAL SYSTEMS CORP., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MATSUMOTO, KAZUYA;KARAKI, KAZUHISA;HASEGAWA, MAMORU;AND OTHERS;SIGNING DATES FROM 20131129 TO 20131203;REEL/FRAME:031939/0386 |
|
AS | Assignment |
Owner name: OLYMPUS CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OLYMPUS MEDICAL SYSTEMS CORP.;REEL/FRAME:036276/0543 Effective date: 20150401 |
|
AS | Assignment |
Owner name: OLYMPUS CORPORATION, JAPAN Free format text: CHANGE OF ADDRESS;ASSIGNOR:OLYMPUS CORPORATION;REEL/FRAME:042068/0585 Effective date: 20160401 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 4 |